I spoke to my father - my father's from Pakistan and he's also a lawyer - I said to him, "Well what does the Shari'a say?" And he said, "Well, of course it doesn't justify suicide bombs," but he didn't seem to know where the Shari'a came from or what it was all about. The more I asked people in my family as well as friends, the more I realized that there seemed to be widespread ignorance in the Muslim community. And that's something which I actually found to be the case over the next two and a half, three years I spent writing the book.

I think it's important to understand Shari'a to be rooted in history - what we know about the history and what we don't know about the history. So then, if people want to argue, at least they're arguing from the same point and we know what we know, and we know what we don't know.

The one fatwa that everyone here is probably familiar with is the Salman Rushdie fatwa, but a fatwa doesn't have to be a violent thing at all. A fatwa is simply a ruling on Islamic law; there can be fatwas on clothing.

Shari'a is not just the Qur'an, you see Shari'a is comprised according to all the doctrines. There's consensus and analogy - argument by analogy. These are the four components in the Shari'a. An orthodox Sunni would not accept that the Shari'a was simply comprised of the Qur'an itself and actually there are people who say that it's heretical to believe that. They have to say that because if they don't say that then they would have to accept that, for example, stoning is not a punishment which appears in the Qur'an - it doesn't.

There's crucial distinction that has to be drawn between the Shari'a, which is this hugely expansive vision of cosmic order that I've been describing, and principles of Islamic law, known in Arabic as "Fiqh" - a word that means understanding. If you're a devout Muslim, you don't argue against the Shari'a; the Shari'a is the path that God has laid down. But what you can do, and what people are doing all the time, is arguing over the correct interpretation of the Shari'a, arguing over the Fiqh. That's something that has been going on throughout Islamic history.

Whereas a man is entitled to marry three more times and that fosters great abuse, even scholars accept that. So certainly since the 1980s Shari'a courts have been established and they allow for women to go to them and they basically grant them annulment. It's not a civil divorce, they don't have the right to grant alimony or maintenance or custody.

The Shari'a itself - this is possibly a kind of verbal debate - is understood to be something different from the Fiqh, and the Fiqh is the man-made element and the Shari'a is theoretically the divine element but it depends on one's personal beliefs.